SDL: pthread/SDL_systhread.c: always include errno.h

SDL Commits
1 
From e8c48981f9a9685bfd93aecca1a19bebda4d4d3c Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Sat, 5 Feb 2022 08:56:56 +0300
Subject: [PATCH] pthread/SDL_systhread.c: always include errno.h

fixes build for several targets after commit 87b02d3 for bug #5283.
---
 src/thread/pthread/SDL_systhread.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/src/thread/pthread/SDL_systhread.c b/src/thread/pthread/SDL_systhread.c
index 75a03abe4ab..3b3f40fa182 100644
--- a/src/thread/pthread/SDL_systhread.c
+++ b/src/thread/pthread/SDL_systhread.c
@@ -30,21 +30,17 @@
 #endif
 
 #include <signal.h>
+#include <errno.h>
 
 #ifdef __LINUX__
 #include <sys/time.h>
 #include <sys/resource.h>
 #include <sys/syscall.h>
 #include <unistd.h>
-#include <errno.h>
 
 #include "../../core/linux/SDL_dbus.h"
 #endif /* __LINUX__ */
 
-#if __RISCOS__
-#  include <errno.h>
-#endif
-
 #if (defined(__LINUX__) || defined(__MACOSX__) || defined(__IPHONEOS__)) && defined(HAVE_DLOPEN)
 #include <dlfcn.h>
 #ifndef RTLD_DEFAULT